The present invention relates to Huber needle assemblies, and more particularly to a safety device for a Huber needle assembly.
With the passage of the needlestick safety act (Public Law 106-430, 106th Congress, H.R. 5178) with an effective date of Apr. 18, 2001, the Occupational Safety and Health Administration (OSHA) now requires affected employers, primarily healthcare institutions, to consider and implement new technologies when they update their “exposure control plan.” Included are “engineering controls” (devices) to mitigate the possible exposure to blood-borne pathogens via accidental needle sticks.
Various engineering controls exist to protect nurses, technicians and caregivers from accidental needle sticks from injection needles, venous cannulation devices, skin closure devices and scalpels. In the area of subcutaneous medication device access (port), in which a Huber needle assembly is employed, a number of devices exist that offer a margin of protection from accidental needle sticks when removing the needle, or “sharp,” from the port. One danger from de-accessing a subcutaneous port is the result of how the port itself is constructed. The port is a metal or plastic device with a pierceable area, often made of a silicone compound, through which access is made by a Huber needle to the vascular system for the purpose of infusing medication into the body. The Huber needle is specially designed to reduce the possibility of mechanically damaging and/or removing a portion of the the pierceable area as it is punctured, and which is referred to as “coring.” This coring limits the number of times a port can be accessed. To combat this damage and extend the useful life of the port, the silicone compound is inserted under pressure into the device. It is this pressure that is the arbiter of the danger to the clinician removing the needle used to cannulate the port.
There are some devices that provide at best limited protection to a clinician when removing the needle. For instance, in some devices, a safety capture device uses a latching feature such as “hooks” or “fingers” that are manually secured around the needle by forcing the needle between them. But these devices require the clinician to grasp the needle with one hand, and secure it with a latching cover with the other hand. These devices can be rearmed by simply defeating the latching feature, such as spreading the hooks or fingers, which could release the needle.
Another danger in removing the needle is the resistance to extraction exerted on the needle by the compressed silicone compound on the port the needle inhabits. Due to this resistance, the clinician may use both hands to remove the needle to prevent pain at the insertion site as well as manipulate the safety capture device to safely cover the needle. When the needle “clears” the resistance of the silicone barrier the individual removing the needle will involuntarily compensate for the loss of resistance by reversing the motion and redirect the needle back towards the patient and their fingers being used to stabilize the area of the patient's skin surrounding the subcutaneous port.
The other problem with these designs is that the force necessary to push the needle through the latching cover is substantial. If the clinician uses a strong enough spring to force the needle through the capture feature to assure a 100% capture rate it could pinch the patient as the swing arm travels and “pins” some sensitive skin between the partially indwelling needle and the arm of the safety device. If you use a weaker spring you run the risk of not having the needle force necessary to spread the fingers and secure the needle. Not unlike a yard gate latch that incorporates two opposing “hooks” held in closure by a spring. The latch pin attached to the gate section has to overcome the force of the spring to spread the hooks to engage the latch.
No passive device existed that would allow a single clinician remove and flush the device at the same time.